Polythiophene – Recent development of photovoltaic cells fullerene research phase

Polythiophene and its derivatives are a class of typical low cost and can be an organic semiconductor material synthesized macro, one of the candidate is an organic photovoltaic material suitable for the future commercialization. In polythiophenes have been reported in the donor material, an ester group thiophene build polythiophene derivative cell is a photovoltaic highest performance donor material, device efficiency can reach to 12%, but between the still and the current efficiency System there is a big gap. Morphology of the active layer is a key factor in the performance of PV. In-depth understanding of the phase separation structure of such low-cost organic photovoltaic blends and its influencing factors, the establishment of a comprehensive system of molecular structure – film phase – further optimization and development and industrialization of the relationship between OPV photovoltaic performance of blends advance the process of great significance. 天津大学《Joule》:聚噻吩-非富勒烯光伏电池相态研究的新进展 More recently, Professor Hou Yan Geng School of Materials Science and Engineering, Tianjin University, and the research team, Professor Ye Long ester-substituted polythiophene donor material PDCBT-Cl (Macromolecules, 2019, 52, 4464-4474) for the study, five different selected terminal groups or having non-representative fullerene acceptor material (ITIC-Th1, ITIC, IT4F, IDIC and Y6) of the intermediate unit, the formation kinetics and thermodynamics blending different angles relative to the system differences states conducted intensive studies, systematic analysis of such blends of amorphous crystalline – amorphous interaction parameter χaa, crystalline – amorphous quenched interaction parameter and the degree of off χca morphology of the active layer, the establishment of a blend system molecular structure – a thin film phase – the relationship between the device performance. Found, unlike with great success to Y6 and polymer blends benzodithiophene units acquired based on the photovoltaic efficiency, PDCBT-Cl and Y6 matching obtain only ~ 0.5% of energy conversion efficiency, because its essence PDCBT-Cl highly compatible with Y6, blends in a single phase, phase separation hardly occurs. And PDCBT-Cl: ITIC-Th1 blends having a suitable compatible acceptor material, by blending the film after treatment may precise composition of the mixed phase locked near the percolation threshold facilitate electron transport, and the active a thin film layer can be formed more ordered molecular packing, facilitate carrier transport, thereby obtaining a device efficiency of over 12%. Based on the 5 kinds blends system, to further improve their polythiophene – PV non-fullerene BlendsPerformance optimization strategy is proposed from both structural and molecular design and device structures. The work cost molecule polythiophene system design and the regulation of aggregate structures having great significance. Compatibility and acceptor molecules to the ordered material to polythiophenes: Non important influence fullerene film morphology and device performance system. Non fullerenes and acceptor materials polythiophene thiophene need to obtain a high hard material is thermodynamically matching system highly compatible device performance. This study shows that amorphous by physical parameters such as – amorphous interaction parameter χaa, crystalline – amorphous interaction parameter χca like may polythiophene molecular structure design system, and the regulation of film morphology matching material is provided to the recipient as a guide to further promote The organic solar cell commercialization process.

Blends χ-φ phase diagram yl QSAR FIG 1. PDCBT-Cl typical non-fullerene acceptor material

In the correlation result \”Optimization Requirements of Efficient Polythiophene: Nonfullerene Organic Solar Cells \”was published in the authoritative journal energy materials\” on Joule \”, the first author of the study as a doctoral School of materials Science and Engineering of Tianjin University Liang Ziqi, corresponding author Professor Dr. Ye Longhu Li Miao. Co-authors of the paper include Prof. Harald Ade Tianjin University Professor Hou Yan Geng, Deng Yunfeng associate professor and North Carolina State University. When the research was supported by the National Natural Science Foundation of China, and organic light emitting materials and devices supported by the National Key Laboratory Foundation and the Shanghai synchrotron radiation light source. The full text link: https://doi.org/10.1016/j.joule.2020.04.014